VOT

Voice Onset Time (VOT): Amount of time between the burst of air released and the start of voicing

Voice Onset Time or VOT is the amount of time between the burst of air released and the start of voicing

VOT can be shown on an “S” curve (Sigmoid Function):

  • At 0-30ms: one distinct sound is heard
  • 30-60ms: the listener is still believing that they are hearing that first distinct sound and have not noticed a difference
  • 60ms and onward: suddenly the listener hears a completely new sound but was unaware of the gradual change

This is an example of a typical VOT “S” Curve, but with different ms measurements:

Categorical Boundaries

Speakers of different languages have different categorical boundaries:

  • English speakers can hear the difference between voiced and voiceless aspirated sounds, but cannot hear a difference in voiceless unaspirated sounds.
  • Spanish speakers can hear the difference between voiced and voiceless unaspirated sounds, but cannot hear a difference in voiceless aspirated sounds.
  • Thai speakers can hear a difference between all three sounds.

References

Pisoni, D. B. (n.d.). Identification and discrimination of the relative onset time of two component tones: implications for voicing perception in stops. Unpublished manuscript, Department of Psychology, University of Texas, Austin, Texas. Retrieved from homepage.psy.utexas.edu/homepage/class/psy394U/Diehl/Pisoni.ppt

Repp, B.H. (1991). Effects of preceding context on the voice-onset-time-category boundary. Journal of Experimental Psychology: Human Perception and Performance, 17(1), Retrieved from http://psycnet.apa.org/index.cfm?fa=buy.optionToBuy&id=1991-17436-001